This invention relates to isopropoxy- and phenoxyaminophenoxycyclotriphosphazenes and to a process for producing same.
It is reported by Kumar et al in "High-Strength Fire- and Heat-Resistant Imide Resins Containing Cyclotriphosphazene and Hexafluoroisopropylidene Groups", Journal of Polymer Science, Volume 22, pages 927-943 (1984), John Wiley & Sons, Inc., that triphenoxy-tris(aminophenoxy)cyclotriphosphazenes are used as intermediates to produce maleimidophenoxycyclotriphosphazenes which are linked by hexafluoroisopropylidenediphthalimide groups to yield high strength, fire- and heat-resistant polymers. In "Polybismaleimide Containing Tetrakisphenoxycyclotriphosphazenes", D. Kumar, Journal of Polymer Science, Volume 23, pages 1661-1670 (1985), John Wiley & Sons, Inc., it is reported that tetraphenoxy-bis(aminophenoxy)cyclotriphosphazene is an intermediate used in the production of tetraphenoxy-bismaleimidocyclotriphosphazene which is polymerizable to produce a heat-resistant polymer.
Not only are these phenoxyaminophenoxycyclotriphosphazene compounds useful as intermediates, but it has also been found that they exhibit flame-retardant properties in flexible foam compositions.
The processes described for producing triphenoxy-tris(aminophenoxy)cyclotriphosphazene and tetraphenoxy-bis(aminophenoxy)cyclotriphosphazenes can generally be described by the two-step sequence of: (1) reacting triphenoxy-trichlorocyclotriphosphazene, in the case of synthesizing the former, and tetraphenoxy-dichlorocyclotriphosphazene, in the case of synthesizing the latter, with sodium nitrophenoxide. The resultant products are, respectively, triphenoxy-tris(nitrophenoxy)cyclotriphosphazene and tetraphenoxy-bis(nitrophenoxy)cyclotriphosphazene. These products are then subjected to catalytic hydrogenation by contacting same with a catalyst, such as platinum oxide, in the presence of hydrogen gas. While these processes achieve their intended purpose, they are disadvantaged in that they are multistepped, require an expensive catalyst and use an explosive gas, i.e., hydrogen.
It is therefore an object of this invention to provide a noncatalytic one-step process for the production of isopropoxy- and phenoxy-aminophenoxycyclotriphosphazenes. The process does not involve the use of hydrogen gas.